Low Energy BCl3 Plasma Doping of Few-Layer Graphene

In this paper, we use low energy BCl3 plasma for the doping of graphene, and investigate its effect on graphene sheet resistance. In particular, for few-layer graphene, we use a cyclic trap-doping technique to control the dopants between the graphene layers. By using the cyclic tra-doping with the low energy BCl3 plasma, we obtain significant reduction of sheet resistance (similar to 75%), while maintaining high optical transparency, flexibility, conductivity, and thermal stability. Raman data show that the graphene layers are p-type doped with no noticeable damage during the doping. By optimizing the doping condition, we obtain sheet resistance and optical transmittance of BCl3 doped trilayer graphene of 100 Omega/sq and 92% at 550 nm, respectively, which is very compatible with flexible display devices.